What is the normal output voltage range of a 24v lifepo4 battery bank?

[Dzl]

I am looking for a DC laptop charger, I plan to have a 24v nominal lifepo4 battery bank, I'm wondering what input voltage range I should be looking for to make sure the charger will be safe/compatible. If I go by the high/low cell voltages it should have a range of at least 20v to 29.2v, but i'm not sure if this is a realistic way to judge battery bank output voltage, or if alternator or scc charging will increase output, if any safety margin is needed, or if I'm even thinking about this right.

Can anyone please advise.

 

[Dzl]

Also, I've come across a ton of cheap products on amazon that say 12v-24v (not 12v/24v or 12v and 24v). In your experience is that truly the voltage range or is that an attempt at saying works with 12v or 24v power sources.

 

[Craig]

what are you going to use for the laptop charger. I have used a DROK buck converter to power things like monitors and routers. I simply program buck converter to necessary output volts and wire up whatever type of connector my device uses. The Buck converter has a 6v to 72 volt input range with steady output of whatever you wish as long as your supply voltage is greater than load voltage.

 

[Dzl]

This is what I'm looking at right now BatPower 90W PD (power delivery) charger

I've become enamored with the USB-PD standard recently (PD = "power delivery"). 1 connector (usb-c), multiple common voltages (5v, 9v, 12v, 15v 20v), same charger/port can be used to charge your phone, tablet, laptop, speaker, powerbank, bluetooth headset, etc, voltage is negotiated between charger and device. Both need to support PD for this automatic negotiation to happen. There are even these little "PD triggers" for DIY projects.

Some random resources on the subject:
USB.org - What is Power Delivery
Adam Welch - Playing with Power Delivery
Great Scott - Here is why USB-C is awesome and how you can use power delivery for your projects

My other options if I can't find a PD device with a high enough input voltage range for 24v

1) Step down to 12v and then use a 12v PD or standard charger to step back up to the laptop charging voltage of 20v
2) Use a buck converter to supply 20v directly to the laptop (though my laptop charges via USB-C so I'm not sure what would be involved in wiring that)
3) Just use an AC charger via inverter

 

[Dzl]

Products on amazon that say 12v-24v usually auto detect the battery bank you have chosen. LiFePo4 battery 13.6v-14.4v is 100% with 12v being <10% left on your battery

Opps, multiply values times 2 for 24v system

So your thinking most Amazon gadgets that say 12-24 mean they will work with 12v nominal and 24v nominal (i.e. 28 volts actual shouldn't hurt it, or pose a safety risk)?

This is my assumption as well but I've also reached out to the company for clarification. More times than not, the support staff/sales staff don't know the answer though with these cheap consumer products.

 

[Craig]

So your thinking most Amazon gadgets that say 12-24 mean they will work with 12v nominal and 24v nominal (i.e. 28 volts actual shouldn't hurt it, or pose a safety risk)?

This is my assumption as well but I've also reached out to the company for clarification. More times than not, the support staff/sales staff don't know the answer though with these cheap consumer products.

I wold say that device would work with your 24 volt system as long as you stay under 30 something volts. I have lots of 12/24 volt gadgets that have never even blinked at 32 volts.